Today the Supreme Court handed down Virginia v. Moore, ruling unanimously in favor of Virginia. Justice Scalia wrote the majority opinion; Justice Ginsburg concurred.

  The gist of Justice Scalia's opinion is that he can't find any authority at all suggesting that the lawfulness of an arrest under state law has ever been relevant to whether an arrest violates the Fourth Amendment. Or perhaps more accurately, he finds himself insufficiently impressed with those cases and authorities that do point in that direction. For example, he gets past United States v. Di Re by saying it was just a case on the federal supervisory power:

Some decisions earlier than these excluded evidence obtained in violation of state law, but those decisions rested on our supervisory power over the federal courts, rather than the Constitution. In Di Re, 332 U. S. 581, federal and state officers collaborated in an investigation that led to an arrest for a federal crime. The Government argued that the legality of an arrest for a federal offense was a matter of federal law. Id., at 589. We concluded, however, that since Congress had provided that arrests with warrants must be made in accordance with state law, the legality of arrests without warrants should also be judged according to state-law standards. Id., at 589--590. This was plainly not a rule we derived from the Constitution, however, because we repeatedly invited Congress to change it by statute—saying that state law governs the validity of a warrantless arrest "in [the] absence of an applicable federal statute," id., at 589, and that the Di Re rule applies "except in those cases where Congress has enacted a federal rule," id., at 589--590.

  If you recall my blog post, Why United States v. Di Re Clearly Was Not A Case On The Federal Supervisory Power, you'll realize how bogus this is, but hey, that's govenment work for you. (Scalia adds a nice touch at the end of the case when he characterizes the Court's decision as "reaffirm[ing] against a novel challenge what we have signaled for more than half a century," something that I suspect Justice Jackson might have found a rather puzzling characterization.)

  Only Justice Ginsburg takes on Justice Scalia's mischaracterization of Di Re in her narrow concurrence;

[O]ur decision in United States v. Di Re, 332 U. S. 581, 587--590 (1948), requiring suppression of evidence gained in a search incident to an unlawful arrest, seems to me pinned on the Fourth Amendment and not to our "supervisory power," ante, at 72[fn2]

[fn2] The Court attributes Di Re's suppression ruling to our "supervisory power," not to "a rule we derived from the Constitution." Ante, at 7. Justice Jackson, author of Di Re, however, did not mention "supervisory power," placed the decision in a Fourth Amendment context, see 332 U. S., at 585, and ended with a reminder that "our Constitution [places] obstacles in the way of a too permeating police surveillance," id., at 595. The Di Re opinion, I recognize, is somewhat difficult to parse. Allied to Di Re's Fourth Amendment instruction, the Court announced a choice-of-law rule not derived from the Constitution: When a state officer makes a warrantless arrest for a federal crime, federal arrest law governs the legality of the arrest; but absent a federal statute in point, "the law of the state where an arrest without warrant takes place determines its validity." Id., at 588--589.

  I don't think Justice Jackson saw that as a choice-of-law rule not derived from the Constitution; In 1948, back before the incorporation of the Fourth Amendment, the only agents regulated by the Fourth Amendment were federal agents. At the time, such a rule would have seemed a plausible way to determine the lawfulness of the arrest, which he, Learned Hand, and the rest had understood as resting on statutory arrest law. But maybe you have to be more of a Fourth Amendment geek than any Supreme Court Justice would be to see that. And in any event, kudos to Justice Ginsburg for at least raising the Di Re issue.

  I plan to blog more on Moore in the future, time-permitting. Stay tuned.